Luminaire, assembly for a grid ceiling, method for installing a luminaire, method for removing a luminaire, and removal tool

ABSTRACT

A luminaire for installing in a grid ceiling includes at least one catch which is arranged in such a way on the luminaire and designed such that the at least one catch snaps into place automatically behind a portion of an element of the grid ceiling and thus engages behind the portion of the element of the grid ceiling in order to hold the luminaire on the grid ceiling. In addition, an assembly for a grid ceiling includes at least one ceiling profile element and at least one such luminaire.

FIELD OF THE INVENTION

The present invention relates to a luminaire for installing in a gridceiling. In addition, the invention relates to an assembly for a gridceiling, a method for installing a luminaire, a method for removing afitted luminaire, and a removal tool.

BACKGROUND OF THE INVENTION

Building interiors in particular, for instance offices or businesspremises, are often fitted with suspended ceilings. Such ceilings can bedesigned to have a supporting structure and ceiling panels that formcomponents of what is known as a grid ceiling system.

Suitable luminaires can be installed in the region of the ceiling toprovide lighting to an interior fitted with a suspended ceiling. Inparticular, such luminaires can be integrated in the suspended ceilingfor this purpose.

Owing to the installation position in the ceiling region, which oftenmeans that the installation engineer must work above head height, itwould be desirable if installation of the luminaire in the region of agrid ceiling could be accomplished as quickly and simply as possible andat low cost. In addition, it would be desirable, for instance duringalterations to the interior or if the luminaire needs to be taken outfor other reasons, if an installed luminaire could be removed easily andin a manner requiring as little time and labour as possible.

SUMMARY OF THE INVENTION

In view of the above, one idea of the invention is thus to provide aluminaire that can be installed easily in the region of a grid ceilingand preferably can also be removed again easily. In addition,corresponding improvements should be made to a grid ceiling. It is alsoan object of the invention to create a method for easily and quicklyinstalling a luminaire improved in such a way, and a method for removingsuch a luminaire easily and quickly, and to provide a suitable tool forthis purpose.

Accordingly, a luminaire for installing in a grid ceiling is proposedthat has at least one catch. According to the invention, the at leastone catch is arranged in such a way on the luminaire and designed suchthat the at least one catch snaps into place automatically behind aportion of an element of the grid ceiling during installation of theluminaire. By snapping into place automatically, the at least one catchengages behind the portion of the element of the grid ceiling in orderto hold the luminaire on the grid ceiling.

In addition according to the invention, an assembly for a grid ceilingis proposed that comprises at least one ceiling profile element and atleast one such luminaire according to the invention. In this assembly,at least one movable catch of the at least one luminaire engages behinda portion of the ceiling profile element of the grid ceiling, theengaging of the catch behind the ceiling profile element holding the atleast one luminaire on the grid ceiling.

The invention also provides a method for installing a luminaireaccording to the invention in a grid ceiling. The method comprises thesteps of:

-   -   providing a luminaire according to the invention; and    -   moving the luminaire relative to at least one element of the        grid ceiling, which element is arranged and fixed in a        predefined final position assigned to the element for the        purpose of forming the grid ceiling, in such a way that at least        one catch of the luminaire snaps into place automatically behind        a portion of the element of the grid ceiling, and by the        automatic snapping into place engages behind the portion of the        element of the grid ceiling in order to hold the luminaire on        the grid ceiling.

In addition, the invention provides a method for removing a luminaireaccording to the invention that is installed in a grid ceiling. Themethod comprises the steps of:

-   -   inserting a designated removal tool in an insertion direction        from a visible side of the grid ceiling into a gap between an        element of the grid ceiling and the luminaire;    -   the removal tool engaging over a movable catch of the luminaire,        which catch engages behind a portion of the element of the grid        ceiling in order to hold the luminaire on the grid ceiling; and    -   pulling on the removal tool in a direction substantially        opposite to the insertion direction in order to apply to the        catch a force that causes the catch to disengage from the        portion of the element; when being pulled, the removal tool is        guided in the gap between the element and the luminaire.

In addition, a removal tool is proposed for removing a luminaireaccording to the invention that is installed in a grid ceiling, whichremoval tool can be used in particular for removing the luminaire bymeans of the above method according to the invention. The removal toolhas a first portion, a second portion connected to the first portion andextending laterally transverse to the first portion, and a tongueconnected to the second portion. In this case, the tongue extends awayfrom the second portion in substantially the same direction as the firstportion. In some regions the first portion is in the form of a handleportion for handling the removal tool. The second portion, the tongueand part of the first portion delimit a recess, part of which recess isdesigned to be a catch holding region for holding a portion of a catchof the luminaire. When a portion of the catch is received in the catchholding region and rests against the second portion of the removal tool,then the tongue protrudes past the catch in the extension direction ofthe tongue from the second portion.

One idea forming the basis of the present invention is to use thegeometry of at least one element of a grid ceiling in order to be ableto fix the luminaire without tools in the region of the grid ceiling bymeans of a catch provided on the luminaire snapping into placeautomatically. This makes the luminaire far easier to install, which canprove advantageous especially when there are a relatively large numberof luminaires to install and where there are large ceiling surfaceareas, as can arise in relatively large offices or business premises,for example. A grid ceiling having an assembly according to theinvention can thus be installed more quickly and at a lower cost. Inaddition, obtrusive fixing elements that can be seen from the visibleside of the grid ceiling are not required for the luminaire or the like,with the result that the grid ceiling containing the installed luminairecan be designed advantageously from the aesthetic viewpoint to beparticularly attractive. The removal method provided by the inventionand the removal tool allows rapid and safe removal of the luminaire ifrequired. In addition, the protrusion of the tongue of the removal toolbeyond the catch avoids the removal tool becoming caught and jammed whenreleasing the catch, because the tongue formed in this manner canadvantageously be guided during the detachment process in a gap betweenthe luminaire and the element of the grid ceiling behind which the catchis engaged

An element of the grid ceiling shall be understood here to refergenerally to a component of the grid ceiling, which component can havethe widest variety of designs. For example, the element might be in theform of a profile or rail, such as a ceiling-profile element forinstance, or else in the form of a panel or sheet, such as, forinstance, in the form of a ceiling tile containing a cutout foraccommodating the luminaire or the like, or in another form.

Advantageous embodiments and developments of the invention appear in thedependent claims and in the description with reference to the figures inthe drawing.

In one embodiment, the at least one catch has a sloping slide. Thesloping slide is arranged and oriented such that during installation ofthe luminaire, the sloping slide faces the grid ceiling and is at anangle to a direction along which the luminaire can be introduced intothe grid ceiling in order to install said luminaire. This can makeinstalling the luminaire even easier in that during the installationprocess, regions of the grid ceiling element can slide over the slopingslide and thereby depress the catch.

In another embodiment, the at least one catch is spring-loaded. Thecatch thereby snaps into place reliably behind the portion of theelement of the grid ceiling.

In one embodiment, the at least one catch is arranged and spring-loadedsuch that on snapping into place it returns automatically to a positionin which the at least one catch protrudes beyond an edge of theluminaire, in particular a lateral edge thereof. This makes it easier torelease the catches later in order to remove the luminaire.

In one embodiment, the luminaire also comprises a catch housing. In thiscase, the at least one catch is displaceably guided in the catchhousing. The catch housing can thus allow the catch to be guided in areliable and defined manner.

In another embodiment, the at least one catch is displaceably guided inthe catch housing. A guide allowing displacement of the catch can beimplemented relatively easily and in a small amount of space. Inaddition in this case, it is easily possible in particular to bring intocontact with the element a sufficiently large retaining surface of thecatch for holding the luminaire.

According to another embodiment, the at least one catch and the catchhousing, in which the at least one catch is guided, form components of acatch unit. In addition in this development, the luminaire comprises atleast one groove in which the catch unit is fixed. The catch unit canthus in particular advantageously be preassembled and fixed inside thegroove at the desired position during assembly of the luminaire.

In one embodiment, the catch unit is clamped in the groove and therebyfixed therein at least along the groove. Fastening the catch unit in thegroove by clamping can allow the catch unit to be fixed reliably in afriction fit against moving along the groove, thereby avoiding makingholes and the like in the luminaire for fixing the catch unit. Inaddition, the clamping can be released again, if the need for thisarises, and the catch unit can be moved in the groove and reclamped in adifferent position.

In a further embodiment, the luminaire has a plurality of catches,wherein at least two of the catches are arranged on opposite sides ofthe luminaire. The luminaire can thereby advantageously engage behindelements of the grid ceiling adjacent to opposite sides of the luminairein order to hold the luminaire on the ceiling even more reliably.

In particular, the plurality of catches can have the same design. Thisallows further cost savings in the manufacture of the luminaire and theassembly for the grid ceiling owing to the lower number of differentindividual parts to be produced.

In another embodiment, a plurality of catch units can be provided, eachof which comprises one catch housing and one catch and whichadditionally are each fixed to the luminaire.

In another embodiment, at least two grooves can be provided for thispurpose on the luminaire, which grooves are arranged on different sidesof the luminaire and are intended to receive the catch units. Such anarrangement of the grooves combined with a plurality of catch units canoffer a variety of options for arranging the catches on the luminaire.

According to a another embodiment, the luminaire comprises at least twocatches of substantially the same design arranged on one side of theluminaire spaced apart from one another along a longitudinal directionof the luminaire. This embodiment allows even a relatively longluminaire to be held on the grid ceiling even more reliably. Forparticularly long luminaire lengths, it can be useful in particular tohave more than two catches arranged spaced apart from one another on onelongitudinal side of the luminaire in order to avoid the luminairesagging under its own weight, for instance.

In another embodiment, the luminaire is equipped with at least fourcatches that are preferably designed and guided in the same manner.According to this embodiment, two of the catches are arranged spacedapart from one another on a first side of the luminaire, while two moreof the catches are arranged spaced apart from one another on a secondside of the luminaire. In this way, the luminaire can be inserted easilybetween two elements of the grid ceiling without being tilted during theinstallation, and can be installed reliably on the grid ceiling bysnapping the catches into place behind portions of said elements.

In one embodiment, the catches can advantageously be made from a metalmaterial, thereby achieving a more robust catch that can withstand agreater load.

In another embodiment, the element of the grid ceiling behind which thecatch engages is a profile, in particular a ceiling profile element ofthe grid ceiling.

In the present application, a ceiling profile element shall beunderstood to mean generally a profile element that forms a component ofthe grid ceiling.

According to another embodiment, the ceiling profile element can be inthe form of a component of a supporting structure of the grid ceiling,it being possible for the ceiling profile element to be designed inparticular for supporting ceiling elements of the grid ceiling. By meansof this embodiment, a ceiling profile element of the supportingstructure can be used advantageously also for attaching the luminaireeasily and quickly. The ceiling elements of the grid ceiling can be inthe form of ceiling panels, ceiling tiles or the like, for example. Inparticular it can be provided that the ceiling profile element can bearranged and fixed separately from the ceiling elements in its finalposition, for instance in the region beneath a bare ceiling.

In an alternative embodiment, the ceiling profile element can beintegrated in a ceiling element, for instance a ceiling panel or ceilingtile, or rigidly connected thereto. For instance in a variant of thisembodiment, the ceiling element can be provided with a cutout, one ormore ceiling profile elements being provided in the edge region of thiscutout and being connected to the ceiling element, for example in theform of a shaft or the like.

According to one embodiment, the ceiling profile element is designed tohave an inverted T-shape at least in one region of its cross-section. Inthis embodiment, the at least one catch of the at least one luminaireengages behind a portion of a flange segment of the inverted T-shapedregion. Such a ceiling profile element can be advantageous for instancein terms of the mechanical load it can withstand. The cross-section ofthe ceiling profile element can have a different design from this,however, in other embodiments.

According to a further embodiment, the assembly also comprises at leastone ceiling element, part of which rests on the ceiling profile element,it being possible for the at least one luminaire to in particular besubstantially flush with the ceiling element or the ceiling profileelement or both on a visible side of the grid ceiling. Such a flushassembly can be preferable from the aesthetic viewpoint.

In a development, the ceiling profile element can be configured as acomponent in the form of a rail, in particular made of a metal material.

In a further embodiment, it can be provided that at least two elementsof the grid ceiling, in particular two ceiling profile elements, areeach arranged at a respective predefined final position assigned to theelement in order to form the grid ceiling, and are fixed in the finalposition. For instance, the elements can be arranged and fastened at apredefined separation from one another that is designed to suit thedimensions of the luminaire. In this embodiment, in order to install theluminaire, said luminaire is inserted between the at least two elements.This is done in such a way that during installation of the luminaire,the at least one catch automatically snaps into place behind a portionof one of the elements of the grid ceiling and thereby engages behind aportion of the element of the grid ceiling in order to hold theluminaire on the grid ceiling.

According to a further embodiment of the installation method, aluminaire that comprises at least two catches arranged on opposite sidesof the luminaire, can be inserted advantageously between the at leasttwo elements in the manner such that each of the catches snaps intoplace behind a portion of an associated element of the two elements.

In a further embodiment of the method for removing the luminaire, whilepulling using the designated removal tool, a force is exerted on thesloping slide of the catch. In particular, it is thereby advantageouslypossible by pulling on the removal tool substantially along thatdirection in which the luminaire is held by the catch, for example alonga direction vertical to the floor, by means of the sloping slide toexert on the catch a force that displaces the catch transverse to thispull direction and thereby disengages the catch from the element of thegrid ceiling behind which it is engaged.

In an embodiment of the removal tool, part of a boundary of the catchholding region is formed by an end edge formed on the second portion andby edge portions of the first portion and of the tongue, which edgeportions are substantially parallel to one another. In addition in thisembodiment, the recess is continued by sloping edge portions of thefirst portion and of the tongue that are joined to the parallel edgeportions of the first portion and of the tongue. In this case, thesloping edge portions run at an angle to the substantially parallel edgeportions of the first portion and of the tongue, and the catch can beintroduced into the catch holding region through a space between thesloping edge portions. The parallel edge portions, which in particularcan run substantially perpendicular to the end edge and in the intendedpull direction of the removal tool, allow the end edge of the recess toslide over the sloping slide of the catch during pulling in order torelease the catch. The sloping edge portion of the tongue allows thecatch to be introduced more easily into the space and the catch holdingregion. This is useful when releasing the catch by introducing theremoval tool through a gap between the luminaire and the element of thegrid ceiling behind which the catch is engaged, because in this case,the catch will often barely be visible from a visible side of the gridceiling. The sloping edge portion of the first portion can help, whenpulling on the removal tool using the handle portion, to apply thepulling force effectively to the catch and to prevent moments about thecatch that might result in the removal tool becoming wedged or jammed.

In a further embodiment of the removal tool, the two sloping edgeportions of the first portion and of the tongue can run substantiallyparallel to each other.

According to another embodiment, the removal tool can be flat in design,in particular made from a flat material, for instance a sheet metal. Aflat removal tool of this type is advantageous for introducing into agap between the luminaire and the element of the grid ceiling whenremoving the luminaire.

In one embodiment, the removal tool can be stamped from a metal sheet,for instance a sheet made of steel or stainless steel. A tool with sucha design is cheap to produce.

The above embodiments and developments can be combined with one anotherin any practical way. Further possible embodiments, developments andimprovements of the invention also include combinations of features ofthe invention that are described above or below with regard to theembodiments, even if these combinations are not mentioned explicitly. Inparticular, in this case a person skilled in the art will also addindividual aspects as improvements or additions to the relevant basicform of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in greater detail below with reference to theembodiments presented in the schematic diagrams, in which:

FIG. 1 shows a perspective view of a luminaire according to anembodiment of the invention;

FIG. 2 shows a perspective enlarged view of a portion of the luminaireof FIG. 1;

FIG. 3 shows a grid ceiling and a luminaire according to the embodimentin a perspective view from below in order to illustrate an installationprocedure, in which the luminaire in FIG. 3 has not yet been broughtinto contact with the grid ceiling;

FIG. 4 shows the grid ceiling and the luminaire from FIG. 3 in a statethat follows the state shown in FIG. 3 during installation of theluminaire, the luminaire in FIG. 4 not yet being fully installed,together with a detail D1 that shows an enlargement of the region of acatch unit of the luminaire in this state;

FIG. 5 shows the grid ceiling and the luminaire from FIG. 3, theinstallation of the luminaire being complete and the luminaire beingfully installed;

FIG. 6 shows the installed luminaire of FIG. 5 together with portions ofthe grid ceiling in a cross-sectional view;

FIG. 7 shows the grid ceiling and the luminaire according to theembodiment in the installed state of FIG. 5, in which, in preparing toremove the luminaire, a removal tool is inserted into a gap between theluminaire and a ceiling profile element of a supporting structure of thegrid ceiling;

FIG. 8 shows the grid ceiling and the luminaire according to theembodiment in a state that follows the state shown in FIG. 7 duringremoval of the luminaire and in which state the removal tool is alreadyinserted in the gap, together with a detail D2 showing the removal toolengaging over a catch of the luminaire, and in which a ceiling elementand regions of a ceiling profile element have been left out for clarity;and

FIG. 9 shows the grid ceiling and the luminaire according to theembodiment during detachment and removal of the luminaire in a statethat follows the state shown in FIG. 8.

The accompanying drawings are intended to provide greater understandingof the embodiments of the invention. They illustrate embodiments and areused in conjunction with the description to explain principles andconcepts of the invention. Other embodiments and many of the statedadvantages are apparent from the drawings. The elements of the drawingsare not necessarily shown to scale.

In the figures, elements that are identical and have the same functionand effect are denoted by the same reference signs unless otherwisestated.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows a luminaire 1 for installing in a grid ceiling according toan embodiment of the present invention. The luminaire 1 has asubstantially rectangular basic shape. A longitudinal direction of theluminaire 1 is labelled in FIG. 1 with the reference sign x, and atransverse direction of the luminaire 1 with the reference sign y. Inthe example shown, a width B of the luminaire 1 can preferably measureapproximately B=100 mm, and a length L of the luminaire 1 approximatelyL=1200 mm, where it shall be understood that these dimensions are onlyspecified here by way of example, and the width B and the length L canbe chosen to have different values from these in numerous useful andadvantageous variants. For example, for a width B of approximately B=100mm, the length L can measure approximately L=2400 mm according to analternative embodiment.

The luminaire 1 is shown in perspective in FIG. 1 such that the upperface of the luminaire 1 that is not visible in the installed state ofthe luminaire 1 can be seen in the figure. In the region of this upperface, the luminaire 1 comprises an electrical connection device 4. Inaddition, FIG. 1 shows a cover 5, which can be in the form of a coverplate for instance. The cover 5 in particular covers electrical and/orelectronic components of the luminaire 1.

As shown FIGS. 1 and 2, the luminaire 1 has on opposite longitudinalsides 7 a, 7 b grooves 8 that extend in the longitudinal direction x ofthe luminaire 1 along the entire length L and are open to the outside.The cross-section of each of the two grooves 8 in the example shown issubstantially constant and substantially T-shaped along the longitudinaldirection x, the arms of the T-shape that point upwards and downwards inthe figure being designed to be relatively short, whereas an opening 8 bof the respective groove 8 is relatively wide in the embodiment shown inthe figures. Thus, undercuts 8 a provided on both sides of the opening 8b of the groove 8 are relatively flat in this example.

In the luminaire 1 shown in FIGS. 1 and 2, a total of four catch units10 are arranged in the grooves 8. Of the catch units 10, two arearranged on a first longitudinal side 7 a of the luminaire 1, and twofurther catch units are arranged on a second longitudinal side 7 b ofthe luminaire 1, which side is opposite the first longitudinal side 7 a.In FIG. 1, only the two catch units 10 on the side 7 a are visible, oneof which is arranged adjacent to an end region 2 of the luminaire 1, andthe other is arranged adjacent to an opposite end region 3 of theluminaire 1. The catch units 10 on the side 7 a are thus spaced apartfrom one another along the longitudinal direction x. Although the twocatch units 10 on the side 7 b are not visible in FIG. 1, in the exampleshown they are arranged approximately symmetrically to the catch units10 on the side 7 a with respect to a centre axis M of the luminaire 1 inthe longitudinal direction x.

If in variants of the embodiment the length L is chosen to be greaterthan L=1200 mm, for example to be 2400 mm, then three or fourspaced-apart catch units 10 can be arranged on each longitudinal side 7a, 7 b of the luminaire 1, which can result in a total number of six orrespectively eight catch units 10 per luminaire. An even greater numberof catch units 10 per luminaire would also be possible.

The catch units 10 of the luminaire 1 have an identical design. Each ofthe catch units 10 comprises a movable catch 13 and a catch housing 15,said catch 13 being arranged and guided in the associated catch housing15 such that it can be displaced in a straight line. In addition, ineach of the catch housings 15 a spring element (not visible in thefigures) is provided that applies spring tension to the catch 13,thereby spring-loading said catch. The catch 13 is made from a metalmaterial in the embodiment.

The catch housings 15 are designed such that they can be inserted intothe grooves 8 along the longitudinal direction x of the luminaire 1.After insertion into the groove 8, the catch housings 15 are each jammedin the respective groove 8 preferably by one or more screws 19, therebyfixing the respective catch unit 10 to the luminaire 1. While theundercuts 8 a hold the catch housing 15 in the transverse direction y,the catch housing 15 is fixed in the longitudinal direction x in thegroove 8 by a friction fit. Fixing the catch units 10 in the groove 8 byclamping offers a variety of options for positioning the catch units 10.

In the state shown in FIGS. 1 and 2, the catches 13 of the catch units10 each protrude outwards under the action of the spring tension beyondan associated lateral edge 6 in the region of the longitudinal side 7 aor 7 b of the luminaire 1, whereas the catch housing 15 does notprotrude beyond this lateral edge 6.

FIGS. 3 to 5 show a grid ceiling 20 having ceiling elements 21 which arein the form of panels in the example shown, and having a supportingstructure for supporting in particular the ceiling elements 21. Thesupporting structure contains ceiling profile elements 28, which can bemade of metal for instance. A visible side of the grid ceiling 20 isdenoted by the reference sign S. The figures show only regions of thegrid ceiling 20, with just portions of two ceiling profile elements 28and of some ceiling elements 21 being visible. The two ceiling profileelements 28 shown in FIGS. 3 to 5 run as profile rails for example in asubstantially horizontal direction and substantially parallel to eachother at a separation A, as indicated in FIG. 3 and also in FIG. 6.

FIG. 3 also shows a luminaire 1 according to the embodiment in aposition below the two ceiling profile elements 28. The luminaire 1 isintended to be installed in the space between the two ceiling profileelements 28 shown, in such a way that a bottom face of the luminaire 1is approximately flush with the ceiling elements 21 and the ceilingprofile elements 28. On this bottom face, the luminaire 1 has a lightexit region 9, which in this example is substantially rectangular. Forexample, the light exit region 9 can be formed by a transparent pane orpanel which allows light LL (see FIG. 5) provided by the light sources(not shown in the figures) of the luminaire 1 to pass through to theluminaire bottom face and to exit therefrom in order to illuminate theroom to be lit. It shall be understood, however, that the light exitregion 9 alternatively can have numerous different designs.

As shown in FIG. 6, for instance, the ceiling profile elements 28 aredesigned to have a cross-section that in parts is in the shape of aninverted T having a link portion 31 and a belt or flange portion 34. Theflange portion 34 itself continues in a groove-like profile 36 having aninverted T-shaped geometry. In the embodiment shown, the flange portion34 runs substantially perpendicular to the link portion 31.

The catches 13, which can be displaced along the transverse direction y,each have a retaining surface 45 that extends substantially parallel tothe x-y plane spanning the longitudinal direction x and the transversedirection y (see FIGS. 1 and 6). A second surface of the catch 13, onthe other hand, is oriented obliquely to the x-y plane and forms asloping slide 46. The catches 13 are advantageously additionallyequipped with guide grooves 55 in which assigned protrusions 64 providedon the catch housing 15 engage, in a sliding manner, in order to providea further improved displaceable guidance of the catches 13.

For installation, the luminaire 1 is moved upwards in the verticaldirection V onto the ceiling profile elements 28 (see FIG. 3). In thiscase, the sloping slides 46 of the catches 13 face the grid ceiling 20and come into contact with the ceiling profile elements 28 as theluminaire 1 continues to be inserted between the ceiling profileelements 28. Thus, the sloping slides 46 at an angle to the verticaldirection of V cause the spring-loaded catches 13 to be depressed intothe respective catch housings against the respective springs in thedirection of the arrow 51 parallel to the transverse direction y (seethe detail D1 in FIG. 4).

As the luminaire 1 continues to be inserted between the ceiling profileelements 28 in the vertical direction V, the catches 13 arrive behindparts of the flange portions 34 of the ceiling profile elements 28located on both sides of the luminaire 1 (see FIG. 6). Under the effectof the spring tension, the catches 13 automatically move behind therespective flange portion 34 and engage behind a region thereof. Inother words, under the effect of the spring elements, the catches 13return to their respective positions in which the catches 13 protrudebeyond the edges 6.

The luminaire 1 is thus held securely. There is thus no need for a tool,in particular a screwdriver or the like, in order to be able to installthe luminaire 1 in the grid ceiling 20; instead, the luminaire 1 issimply inserted between the profile elements 28 until the catches 13snap into place. Advantageously, a “click” or “snap” sound audible tothe installation engineer can tell the engineer that the catches 13 haveengaged behind the respective profiles 28 assigned to each catch.

As is also evident in FIG. 6, portions 66 of the ceiling elements 21rest on portions of the ceiling profile elements 28 that face away fromthe luminaire 1. The ceiling profile elements 28 form components of thesupporting structure for the grid ceiling 20. In the embodiment shown,in the grid ceiling 20 the luminaire 1 is held between the ceilingprofile elements 28 solely by the effect of the four catches 13, whichengage behind the profile elements 28. The ceiling profile elements 28and the luminaire 1 form components of an assembly 23 for the gridceiling 20.

It should be pointed out that a plurality of luminaires 1 can beinstalled adjoining one another in their longitudinal direction x in thesame way between the ceiling profile elements 28.

FIGS. 7, 8 and 9 show a removal of the luminaire 1 by way of example. Inorder to remove the luminaire 1, a removal tool 78 or a plurality ofidentical removal tools 78 are used (see FIG. 7). The removal tool 78takes the form of a sheet metal part, for instance stamped from sheetsteel, having a sheet thickness t of approximately t=1 mm for example.The removal tool 78 is used for releasing or disengaging the catches 13and can thus also be referred to as a release sheet.

As is illustrated clearly in particular in the detail D2 in FIG. 8, theremoval tool 78 has a first portion 79, a second portion 82 connected tothe first portion 79 and a tongue 91 connected to the second portion 82.The first portion 79 is elongated, extending along a main extensiondirection H1, and is provided with a circular hole 89 in a first endregion 80. That portion of the first portion 79 which is provided withthe hole 89 forms a handle portion 100 of the tool 78.

The second portion 82 is joined to the first portion 79 in a second endregion 81 of the first portion 79, said second portion 82 extendingtransverse to the first portion 79 and laterally away therefrom along amain extension direction H2. At a far end 83 of the second portion 82from the end region 81, a tongue 91, which is narrower and shorter thanthe first portion 79, extends in the same direction as the first portion79 away from the second portion 82. A main extension direction H3 of thetongue 91 is substantially parallel to the main extension direction H1of the first portion 79. The first portion 79, the second portion 82 andthe tongue 91 thus form approximately an asymmetric U-shape, one arm ofwhich is designed to be significantly shorter and narrower.

In order to remove the luminaire 1, the removal tool 78 is introduced inthe direction of the arrow 85 (see FIG. 7) from the visible side S intoa gap 25 between the lateral edge 6 of the luminaire 1 and the adjacentceiling profile element 28. In the embodiment, the tool is introducedsubstantially along the vertical direction V. In order to locate fromthe visible side S the position of the catch 13 on an installedluminaire 1, the removal tool 78 can be moved along the luminaire 1through the gap 25.

The catch 13 can thus be located by the removal tool 78, i.e. theremoval tool 78 encounters the catch 13. Then, by slightly pulling downthe removal tool 78 in an opposite direction to the arrow 85, the catch13 comes to rest in a catch holding region 105 of the removal tool 78,and is thus “captured”, with the removal tool 78 engaging over the catch13 (see FIG. 8).

The catch holding region 105 is located between the tongue 91 on oneside and the first portion 79 on the other side, and is formed by partof a recess 102, which is open towards an outside edge of the removaltool 78 and is delimited by a part of the first portion 79, by thesecond portion 82 and by the tongue 91. In detail, the recess 102 isdelimited by an end edge 103 formed on the second portion 82, an edgeportion 106 of the first portion 79, which edge portion runssubstantially perpendicular to the end edge 103, an edge portion 107 ofthe tongue 91, which edge portion runs substantially perpendicular tothe end edge 103, a sloping edge portion 108 of the first portion 79,which edge portion runs at an angle to the end edge 103, and a slopingedge portion 109 of the tongue 91, which edge portion likewise runs atan angle to the end edge 103. The two edge portions 106 and 107 extendaway from the end edge 103, the edge portion 108 being joined to theedge portion 106, and the edge portion 109 being joined to the edgeportion 107. The edge portions 106 and 107 run substantially parallel toone another. The edge portions 108 and 109 can also be configured to besubstantially parallel to each other. Part of the catch holding region105 is delimited by the end edge 103 and the edge portions 106 and 107.

In the state in which the removal tool 78 is used (see detail D2), theend edge 103 runs substantially perpendicular to a pull direction, whichin the example shown corresponds to the vertical V.

As the detail D2 in FIG. 8 shows, the tongue 91 protrudes along its mainextension direction H3 beyond the catch 13 downwards in the figure, i.e.in the pull direction, and thus extends past the catch 13 when part ofthe catch 13 is held in the catch holding region 105 and, as in thedetail D2, rests against the end edge 103 formed on the second portion82.

Hooking in the removal tool 78 in such a manner that the catch 13 comesto rest in the catch holding region 105 is made easier by the slopingedge portion 109 formed on the tongue 91, which creates a slight taperat the end of the tongue 91.

As shown in FIG. 8, the sloping edge portion 109 faces the first portion79. The sloping edge portion 108 formed on the first portion 79 facesthe sloping edge portion 109. As the removal tool 78 is hooked in, thecatch 13 slides through a space 111 between the sloping end portions 108and 109 into the catch holding region 105.

To release the catch 13, the removal tool 78 is pulled downwards in adirection substantially parallel to the vertical direction V along thearrow 120 (see FIG. 9), i.e. in an opposite direction to that in whichthe removal tool 78 was introduced into the gap 25. The first portion 79and the tongue 91 are guided sideways, i.e. in the transverse directiony, through the gap 25. The fact that the tongue 91 also protrudes beyondthe catch 13 when the end edge 103 rests against the sloping slide 46 ofthe catch 13 means that the removal tool 78 is guided reliably in thegap 25.

During pulling using the hole 89, part of the end edge 103 of the secondportion 82 slides over the inclined sloping slide 46 of the catch 13.Pulling in the arrow direction 120 and the simultaneous support andguidance of the removal tool 78 in the gap 25, in particular against theceiling profile element 28, cause the catch 13 to be depressed into thecatch housing 15 against the spring tension. The catch 13 therebydisengages from the ceiling profile element 28, allowing the luminaire 1to be released.

The necessary pulling force in direction 120 can be applied by hand byan installation engineer. The hole 89 is used here for inserting afinger in order to be able to pull on the removal tool 78 moreeffectively. The slope of the edge portion 108 can be used to ensurethat the line of action of the pulling force is not shifted sidewaysexcessively relative to the catch 13, thereby reducing moments about thecatch 13 and allowing the pulling force to be applied more effectivelyto the catch 13, i.e. pulling occurs more centrally below the catch 13.

FIG. 6, which shows the luminaire 1 installed in the grid ceiling 20,identifies the two gaps 25 between the luminaire 1 and the ceilingprofile element 28 on each side of the luminaire 1, and the respectivegap widths S1 and S2. In the case shown in FIG. 6, the luminaire 1 doesnot sit exactly centrally between the two ceiling profile elements 28,and therefore S1 is larger than S2. In FIG. 6, S1 is larger than thesheet thickness t, i.e. the removal tool 78 can be introduced into thegap 25 on the left in FIG. 6 having the width S1 in order to release thecatch 13.

In the embodiment shown in the figures, which has two catches 13 on eachof the longitudinal sides 7 a and 7 b of the luminaire 1, two removaltools 78 can be used simultaneously. In this case, a removal tool 78“captures”, i.e. engages over, the two catches 13 arranged on the samelongitudinal side 7 a or 7 b of the luminaire 1, in FIG. 6 on the sideof the gap 25 having the gap width S1, which catches are then releasedsubstantially simultaneously, for example, by pulling on the two removaltools at once. In the configurations shown in FIG. 6 by way of example,after releasing the catches 13 of the left side of the luminaire 1 inthe figure, the luminaire 1 can already be tilted out and removed fromthe grid ceiling 20 approximately in the direction of the arrow 136.

The choice of the width B of the luminaire 1 and the separation A of theceiling profile elements 28, taking into account the dimensions of theprofile elements 28 and preferably also the fact that the installedceiling profile elements 28 may not be in their intended position, canbe made such that the gap widths S1 and S2 at least in total are greaterthan the sheet thickness t of the removal tool 78, in other words(S1+S2)>t. A position of the luminaire 1 between the ceiling profileelements 28, in which position at least one of the gaps 25 has a widthS1 or S2 greater than t, can then be achieved if necessary by shiftingthe installed luminaire 1 slightly in the transverse direction y, forinstance.

Of course each of the gap widths S1, S2 individually could also bechosen to be greater than the sheet thickness t, i.e. S1>t and S2>t. Foraesthetic reasons, S1 can advantageously be equal to S2. This isparticularly useful when the luminaire 1, for example because of thedimensions of components of the luminaire 1 which vanish in the gridceiling 20 in the installed state, cannot easily be tilted out afterreleasing the catches 13 of one of the longitudinal sides 7 a or 7 b. Inthis case, the catches 13 on both longitudinal sides 7 a, 7 b of theluminaire 1 are advantageously released by the removal tools 78, and theluminaire 1 is then removed from the grid ceiling 20. For example, thefollowing applies approximately: S1=S2=1.5 mm.

The luminaire 1 can thus be installed between the ceiling profileelements 28 of the grid ceiling 20 by an installation engineer easilywithout using a tool and in a small amount of time. The luminaire 1 canalso be removed easily and quickly. Removal does not require complicatedmanual operations or a screwdriver or the like. Merely one or more ofthe removal tools 78 are used in order to release the catches 13 with asimple pulling action.

Although the present invention has been described fully above withreference to preferred embodiments, it is not restricted to theseembodiments but can be modified in a variety of ways.

In particular, the present invention can be used advantageously forinstalling luminaires on grid ceiling profiles that have the widestrange of cross-sectional shapes, the position of the catches in relationto the additional components of the luminaire being able to be adaptedas necessary to the profile type according to the dimensions andcross-sectional shape of the profile in order to achieve, for example,flush fitting of the luminaire.

In addition, the invention is not limited to luminaires having anelongated basic shape. It is also possible to apply the invention to aluminaire having a square basic shape, for example, or another basicshape, catches being able to be provided if necessary on more than twosides of the luminaire.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The preceding preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention and, withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

The entire disclosures of all applications, patents and publications,cited herein and of corresponding German Application No. 10 2014 213468.4, filed Jul. 10, 2014 are incorporated by reference herein.

1. A luminaire for installing in a grid ceiling, having at least onecatch which is arranged in such a way on the luminaire and designed suchthat the at least one catch snaps into place automatically behind aportion of an element of the grid ceiling during installation of theluminaire and thus engages behind the portion of the element of the gridceiling in order to hold the luminaire on the grid ceiling.
 2. Theluminaire according to claim 1, wherein the at least one catch has asloping slide which is arranged and oriented such that duringinstallation of the luminaire, the sloping slide faces the grid ceilingand is at an angle to a direction along which the luminaire can beintroduced into the grid ceiling in order to install said luminaire. 3.The luminaire according to claim 1, wherein the at least one catch isspring-loaded.
 4. The luminaire according to claim 1, wherein theluminaire also comprises a catch housing and in that the at least onecatch is displaceably guided in the catch housing.
 5. The luminaireaccording to claim 4, wherein the at least one catch is displaceablyguided in the catch housing.
 6. The luminaire according to claim 4,wherein the at least one catch and the catch housing in which the atleast one catch is guided, form components of a catch unit, and in thatthe luminaire comprises at least one groove in which the catch unit isfixed.
 7. The luminaire according to claim 6, wherein the catch unit isclamped in the groove and thus fixed therein at least along the groove.8. The luminaire according to claim 1, wherein the luminaire has aplurality of catches, at least two of the catches being arranged onopposite sides of the luminaire.
 9. The luminaire according to claim 1,wherein the luminaire comprises at least two catches of substantiallythe same design arranged on one side of the luminaire spaced apart fromone another along a longitudinal direction of the luminaire.
 10. Anassembly for a grid ceiling, comprising at least one ceiling profileelement and at least one luminaire having at least one catch which isarranged in such a way on the luminaire and designed such that the atleast one catch snaps into place automatically behind a portion of anelement of the grid ceiling during installation of the luminaire andthus engages behind the portion of the element of the grid ceiling inorder to hold the luminaire on the grid ceiling, wherein at least onemovable catch of the at least one luminaire engages behind a portion ofthe ceiling profile element of the grid ceiling, wherein the engaging ofthe catch behind the ceiling profile element holds the at least oneluminaire on the grid ceiling.
 11. The assembly according to claim 10,wherein the ceiling profile element is designed to have an invertedT-shape at least in one region of its cross-section, and in that the atleast one catch of the at least one luminaire engages behind a portionof a flange segment of the inverted T-shaped region.
 12. The assemblyaccording to claim 10, wherein the assembly also comprises at least oneceiling element, part of which rests on the ceiling profile element, theat least one luminaire being in particular substantially flush with theceiling element and/or the ceiling profile element on a visible side ofthe grid ceiling.
 13. A method for installing a luminaire, comprisingthe steps of: providing a luminaire having at least one catch which isarranged in such a way on the luminaire and designed such that the atleast one catch snaps into place automatically behind a portion of anelement of the grid ceiling during installation of the luminaire andthus engages behind the portion of the element of the grid ceiling inorder to hold the luminaire on the grid ceiling; and moving theluminaire relative to at least one element of the grid ceiling, whichelement is arranged and fixed in a predefined final position assigned tothe element for the purpose of forming the grid ceiling, in such a waythat at least one catch of the luminaire snaps into place automaticallybehind a portion of the element of the grid ceiling, and by theautomatic snapping into place engages behind the portion of the elementof the grid ceiling in order to hold the luminaire on the grid ceiling.14. A method for removing a luminaire having at least one catch which isarranged in such a way on the luminaire and designed such that the atleast one catch snaps into place automatically behind a portion of anelement of the grid ceiling during installation of the luminaire andthus engages behind the portion of the element of the grid ceiling inorder to hold the luminaire on the grid ceiling and installed in a gridceiling, the method comprising the steps of: inserting a designatedremoval tool in an insertion direction from a visible side of the gridceiling into a gap between an element of the grid ceiling and theluminaire; the removal tool engaging over a movable catch of theluminaire, which catch engages behind a portion of the element of thegrid ceiling in order to hold the luminaire on the grid ceiling; andpulling on the removal tool in a direction substantially opposite to theinsertion direction, wherein the removal tool is guided in the gapbetween the element and the luminaire in order to apply to the catch aforce that causes the catch to disengage from the portion of theelement.
 15. A removal tool for removing a luminaire having at least onecatch which is arranged in such a way on the luminaire and designed suchthat the at least one catch snaps into place automatically behind aportion of an element of the grid ceiling during installation of theluminaire and thus engages behind the portion of the element of the gridceiling in order to hold the luminaire on the grid ceiling, and beinginstalled in a grid ceiling, wherein the removal tool has a firstportion, a second portion connected to the first portion and extendinglaterally transverse to the first portion, and a tongue connected to thesecond portion; wherein the tongue extends away from the second portionin substantially the same direction as the first portion; wherein partof the first portion is in the form of a handle portion for handling theremoval tool; wherein the second portion, the tongue and part of thefirst portion delimit a recess, and part of the recess is designed to bea catch holding region for holding a portion of a catch of theluminaire; and wherein when a portion of the catch is received in thecatch holding region and rests against the second portion of the removaltool, and the tongue protrudes past the catch in the extension directionof the tongue from the second portion.
 16. The removal tool according toclaim 15, wherein part of a boundary of the catch holding region isformed by an end edge formed on the second portion and by edge portionsof the first portion and of the tongue, which edge portions aresubstantially parallel to each other, and in that in addition the recessis continued by sloping edge portions of the first portion and of thetongue that are joined to the parallel edge portions, the sloping edgeportions running at an angle to the substantially parallel edge portionsof the first portion and of the tongue, and the catch can be introducedinto the catch holding region through a space between the sloping edgeportions.